Evaluate the following expression when $y = 2$ and $x = 8$. $8$ $y$ $ + 6$ $x$ $ - 7$
Solution: Substitute $2$ for ${y}$ and $8$ for ${x}$ $ = 8{(2)} + 6{(8)} - 7 $ $ = 16 + 48 - 7 $ $ = 57$